1. Field of the Application
The application relates in general to a method and a device for adjusting weighting values in light metering, and more particularly to a method and a device for adjusting weighting values in multi-zone metering.
2. Description of the Related Art
In photography, exposure refers to the total amount of light incident on a photographic medium, such as a photographic film or an image sensor, during taking a photograph. Exposure is measured in lux seconds, and can be computed with respect to exposure value (EV) and scene luminance over a specified area.
At present, various metering modes are provided in camera to allow the user to select the most appropriate one for determining optimal exposure value. In general, the light metering modes include spot metering mode, center-weighted average metering mode, average metering mode, partial metering mode, and multi-zone metering modes.
In conventional, when a human being is photographed, optimal exposure time is determined by analyzing the environment luminance at human face, so that human face is presented by an appropriate luminance in the photograph. In this way, however, a great deal of arithmetical computation and complex image analysis are required for detecting location of the human face, thereby increasing the cost and computational complexity. This way, moreover, requires the whole image to be temporarily stored in the memory, resulting in an increased cost and a lower speed.